closes #25714

Resulting cv2/__init__.pyi entries:

@_typing.overload
def floodFill(
    image: cv2.typing.MatLike,
    mask: cv2.typing.MatLike | None,
    seedPoint: cv2.typing.Point,
    newVal: cv2.typing.Scalar,
    loDiff: cv2.typing.Scalar = ...,
    upDiff: cv2.typing.Scalar = ...,
    flags: int = ...
) -> tuple[int, cv2.typing.MatLike, cv2.typing.MatLike, cv2.typing.Rect]: ...

@_typing.overload
def floodFill(
    image: UMat,
    mask: UMat | None,
    seedPoint: cv2.typing.Point,
    newVal: cv2.typing.Scalar,
    loDiff: cv2.typing.Scalar = ...,
    upDiff: cv2.typing.Scalar = ...,
    flags: int = ...
) -> tuple[int, UMat, UMat, cv2.typing.Rect]: ...

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake